Surveillance of Bacteria Species in Diseased Freshwater Ornamental Fish from Aquarium Shop

Abstract

instance, the study of Dixon and Contreras [1] showed the A survey of bacteria disease infected in freshwater imported ornamental fish. Furthermore, the imported ornamental fish in retail pet shop in Kuala Terengganu, gourami from Asia was found infected by Yersinia Terenggganu, Malaysia was conducted from July to ruckeri, a causative agent of enteric red mouth September, 2007. The collected diseased fish were disease. Therefore, this study was conducted to Dwarf Gourami (Colisa lalia), Discus (Symphysodon survey bacterial disease infected in ornamental fish aequifasciatus), Discus Cichlids (Symphysodon spp.), in Kuala Terengganu, Malaysia and antibiogram of Black Tetra (Gymnocorymbus ternetzi), Swordtail isolated bacteria. Approximately fifty diseased freshwater (Xiphophorus helleri), Platy (Xiphophorus maculates), ornamental fish were collected from an aquarium shop in Variegated platy (Xiphophorus variatus), Black Ruby Kuala Terengganu, Terengganu, Malaysia. They were Barb (Barbus nigrofasciatus), Tiger Barb (Barbus brought back to laboratory using plastic bag filled with pentazona hexazona), Sumatra Barb (Barbus tetrazona), provided aquarium water from pet aquarium shop. Fighting Fish (Betta splendens), Guppy (Poecilia Externally, cotton bud was used to swab onto the lesion reticulata), Mollies (Poecillia spp.) and Silver Catfish while internally intraperitoneal fluid of the diseased fish (Pangasuis sutchi). The bacteria were isolated using was swabbed aseptically and spread on blood agar plate, blood agar plate, cytophaga agar plate, GSP agar plate, cytophaga agar plate, glutamate starch phenol red (GSP) XLD agar plate and MacConkey agar without crystal agar (Merck, Germany) plate, Xylose Lysine Deoxycholate violet plate. The isolated bacteria were identified using (XLD) agar (Merck, Germany) plate and MacConkey agar commercial identification kit. Antibiogram of the isolated without crystal violet (Difco, USA) plate, separately. After bacteria of the present study were also determined. incubation for 24 h, the inoculated plates were examined Nowadays, bacterial disease is a common problem for the suspected single and pure bacterial colony. The faced by ornamental fish industry. Bacterial Gram bacteria were then kept in Trypticase Soy Agar (TSA) negative is recognized as causative agent of many (Merck, Germany) deep tube for identification purpose. bacterial diseases attacking ornamental fish. The identification of the suspected bacteria was done Aeromonas, Citrobacter, Flavobacterium, Edwardsiella, using commercial identification kit (BBL Crystal, USA). Mycobacterium, Pseudomonas and Vibrio are Gram The identified bacterial were cultured in Trypticase negative bacteria usually isolated from the diseased Soy Broth (TSB) (Merck, Germany) for 24 h at room ornamental fish. These bacteria were opportunistic and temperature. The bacterial suspensions were adjusted ubiquitous in the aquatic environment. Many factors into 10 CFU/ml and spread on Mueller Hinton agar could contribute to bacterial infection in ornamental fish (Oxoid, England). Antibiotic disks were then placed on the namely poor water quality, crowding, transportation and MH agar plate and incubated for 24 h at room temperature. inadequate nutrition. Many cases of bacterial infections The diameter of inhibition zones of the each tested in ornamental fish have been reported worldwide. For antibiotic disk was measured and interpreted as sensitive presence of multi drug resistant Edwardsiella tarda in the